Belt sander or grinder



Jan. 21, 1969 HUBBLE 3,422,576

BELT SANDER 0R GRINDER Filed March 19, 1965 i 8 m? mwfiw WH MA Am UnitedStates Patent 3,422,576 BELT SANDER OR GRINDER Ira L. Hubble, Box 9681,Birmingham, Ala. 35215 Filed Mar. 19, 1965, Ser. N 0. 441,073 US. "Cl.51148 1 Claim Int. Cl. B24b 23/06; B24b 21/00; F16h 7/08 ABSTRACT OF THEDISCLOSURE A self-contained, portable, light-weight belt sander orgrinder in which the entire apparatus is mounted on and supported fromthe motor itself and having means to maintain the belt in tension, whichmeans also permits ready changing of the belt when necessary.

This invention relates to an improved, lightweight, portable belt sanderor grinder and contemplates such apparatus which is essentially adaptedfor grinding or sharpening small tools and the like.

An object of my invention is to provide an inexpensive, portable,lightweight belt sander or grinder in which the motor for driving thebelt forms the base or support for the entire device.

An object of my invention is to provide a sander or grinder of thecharacter designated in which behind the belt, in the work area thereof,is provided a back-up member so that when the work piece is pressedagainst the belt, the belt is suitably backed up, thus giving a firm,accurate grinding surface.

Another object is to provide a sander or grinder of the characterdesignated in which the upper or idler pulley is supported from astandard by means of a bellcrank or the like and in which the belt isheld taut by means of a spring having one end anchored on a leverextending from the =bellcrank and the other end anchored to thestandard.

Apparatus illustrating features of my invention and forming a part ofthis application is shown in the accompanying drawings in which:

FIG. 1 is a side elevational view;

FIG. 2 is an enlarged detail side elevational view viewed from theopposite side of FIG. 1;

FIG. 3 is an enlarged fragmentary front elevational view taken from theside toward which the work is applied to the belt; and,

FIG. 4 is a detail sectional view taken generally along line 4-4 of FIG.2.

Referring now to the drawings for a better understanding of my inventionI illustrate the same as embodying a small fractional horsepower motorindicated generally by the numeral 10. As customary, the motor embodiesa base 11 and an output shaft 12.

Secured to an end of the motor is a bracket 13. Secured to the bracketand projecting upwardly, laterally removed from a vertical plane withinwhich is included the output shaft 12, is a standard 14.

At the top of the standard is a horizontally disposed bearing 16.Passing through the bearing 16 is a pin 17. Fast on one end of the pin17 is an arm 18 and fast on the other end is an arm 19.

Mounted in the forwardly extending portion of the arm 18 is a bearingpin 21 for rotatably supporting an idler pulley 22. It will be seen thatthe pin 21 is also horizonta1 ly disposed and is included within thevertical plane which also includes the output shaft 12. Thus, pulley 22and a lower, driven pulley 23 fast on the shaft 12 are in alignment. Aflexible sanding or grinding belt 24 passes over the pulleys.

Patented Jan. 21, 1969 The belt is held taut by means of a spring 26having one end secured at 28 to the standard and the other end securedat 29 to the lower end of the arm 19. The pulleys are crowned as at 30,thus to hold the belt in alignment while the machine is operating.

Projecting forwardly from the standard 14 is a platelike member 31. Onthe forward end of the plate member 31 is a vertically directed back-upmember or platen 32 which is adapted to back up the belt in the areawhere the work piece is to be applied thereto. The member 31 may besecured to the standard by means of a screw or the like 33 and the endof the screw 33 may project to provide the attaching point 28 for thespring 26.

In view of the foregoing the method of constructing and using myimproved sander together with the advantages thereof "may now beexplained and understood. With the device constructed as shown it willbe apparent that the motor 10 and its base 11 support the entiresuperstructure. With the belt 24 trained over the pulleys and with themotor in operation it will be apparent that a work piece may be pressedagainst the grinding surface of the belt 24 in the area of the back upor support plate 32. Further, when it is desired to change belts it isonly necessary to pull upwardly, as viewed in FIG. 2, on the lower endof the arm 19, thereby pivoting the arm 18 and hence the idler pulley 22downwardly, thus to loosen the belt whereupon the belt may be slippedoff the pulleys and a new one installed.

In view of the foregoing it will be apparent that I have invented animproved, lightweight and portable sander or grinder which is entirelysupported from the motor which operates the same. My invention thusserves as an adjunct to heavy duty grinding equipment necessary in shopsand the like for maintaining tools. Since the motor itself suports theapparatus it is quite portable and may be taken immediately to the jobwhere needed. In view of the mounting of the upper pulley as shown, thechanging of the belts requires but a few seconds.

While I have shown my invention in but one form, it will be obvious tothose skilled in the art that it is not so limited but is susceptible ofvarious changes and modifications without departing from the spiritthereof, and I desire, therefor, that only such limitations shall beplaced thereupon as are specifically set forth in the appended claim.

What I claim is:

1. In a portable belt grinder,

(a) an electric motor embodying a housing, base and output shaft,

(b) a vertically upstanding standard rigidly secured to the housing andlaterally of .a vertical plane within which is included the longitudinalaxis of the output shaft of the motor,

(c) a first horizontally disposed bearing on the upper end of thestandard,

(d) a pin rotatable in the first bearing,

(e) an arm fixed at one end to the pin and having a second horizontallydisposed bearing at its opposite end, said second bearing having alongitudinal axis coincident with said vertical plane,

(f) a belt pulley rotatable in said second bearing,

(g) a belt pulley fixed to the output shaft of the motor,

(h) an endless, flexible grinding belt passing over the pulleys,

(i) spring means urging the pulley on said arm away from the pulley onthe output shaft, thereby to maintain the belt tight, and

(j) a platen having a flat surface for the belt carried by the standardand against which the rear surface of the belt is pressed when a workpiece is held 3 4 against the front working surface of the belt out-2,780,033 2/1957 Albright 51-148 X wardly of the platen. 3,127,7124/1964 Krogen 51148 References Cited LESTER M. SWINGLE, PrimaryExaminer.

UNITED STATES PATENTS 5 D. G. KELLY, Assistant Examiner.

2,313,254 3/1943 Mead 5l148 2,431,795 12/1947 Elmes s1 141

